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From: Bart Van Assche <bvanassche@acm.org>
To: Keith Busch <kbusch@kernel.org>, Sagi Grimberg <sagi@grimberg.me>
Cc: Christoph Hellwig <hch@lst.de>,
	linux-nvme@lists.infradead.org,
	Bart Van Assche <bvanassche@acm.org>
Subject: [PATCH v3] nvme: Fix handling of large MDTS values
Date: Thu,  1 Apr 2021 18:39:07 -0700	[thread overview]
Message-ID: <20210402013907.10131-1-bvanassche@acm.org> (raw)

Instead of triggering an integer overflow and undefined behavior if MDTS is
large, set max_hw_sectors to UINT_MAX.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Keith Busch <kbusch@kernel.org>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---

Changes compared to v2: reduced the two max_hw_sectors = UINT_MAX statements into a single assignment.
Changes compared to v1: removed a dev_err() call.

 drivers/nvme/host/core.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 40215a0246e4..87d43309742b 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -3123,10 +3123,10 @@ static int nvme_init_identify(struct nvme_ctrl *ctrl)
 
 	atomic_set(&ctrl->abort_limit, id->acl + 1);
 	ctrl->vwc = id->vwc;
-	if (id->mdts)
-		max_hw_sectors = 1 << (id->mdts + page_shift - 9);
-	else
+	if (!id->mdts || check_shl_overflow(1U, id->mdts + page_shift - 9,
+					    &max_hw_sectors)) {
 		max_hw_sectors = UINT_MAX;
+	}
 	ctrl->max_hw_sectors =
 		min_not_zero(ctrl->max_hw_sectors, max_hw_sectors);
 

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             reply	other threads:[~2021-04-02  1:39 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-02  1:39 Bart Van Assche [this message]
2021-04-02  1:49 ` [PATCH v3] nvme: Fix handling of large MDTS values Keith Busch
2021-04-02  5:00 ` Damien Le Moal
2021-04-02  6:35   ` Christoph Hellwig
2021-04-02 16:50 ` Christoph Hellwig

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